The present invention generally relates to a circuit interrupting device used with electrical power distribution systems as protection against a fault current. The circuit interrupting device includes a circuit interrupter and actuator for operating the circuit interrupter with both the circuit interrupter and the actuator being maintained at a potential that is the same as the system potential, allowing for use of less materials and providing a compact design for the device.
Conventional circuit interrupting devices, such as circuit breakers, sectionalizers and reclosers provide protection for power distribution systems and the various apparatus on those power distribution systems such as transformers and capacitor banks by isolating a faulted section from the main part of the system. A fault current in the system can occur under various conditions, including but not limited to lightening, an animal or tree shorting the power lines or different power lines contacting each other.
Conventional circuit interrupting devices sense a fault and interrupt the current path. Conventional reclosers also re-close the current path and monitor continued fault conditions, thereby re-energizing the utility line upon termination of the fault. This provides maximum continuity of electrical service. If a fault is permanent, the recloser remains open after a certain number of reclosing operations that can be pre-set.
However, conventional circuit interrupters, particularly reclosers, are heavy and bulky, and are usually supported in a tank that has to be mounted to the utility pole. This also prevents retro-fitting a conventional recloser with various circuit interrupter mounts, such as a switch or cutout mounting. Also, conventional reclosers cannot be readily removed from the system to both show a visible break in the circuit and facilitate maintenance on the device. Moreover, the internal mechanisms of conventional reclosers are located within the tank and are thus not visible to a lineman. Therefore, the lineman is forced to rely on an indicator mechanism of the recloser to indicate whether the current path is open or interrupted, and thus, safe for the lineman to perform maintenance or repairs. Moreover, conventional reclosers are costly to make due to the amount and type of materials required. Additionally, conventional reclosers must be grounded, and therefore, require additional amounts of insulative material and ground connections. Furthermore, conventional reclosers often require that the electronic control be housed separately from the recloser.
Also, conventional reclosers require additional mechanical parts to provide a trip free mechanism separate from other mechanisms of the recloser. The trip free mechanism prevents closure of the current path during fault conditions. The additional parts increase costs and require a larger housing to contain the additional parts.
Examples of conventional circuit interrupting devices include U.S. Pat. Nos. 6,242,708 to Marchand et al.; U.S. Pat. No. 5,663,712 to Kamp; U.S. Pat. No. 5,175,403 to Hamm et al.; U.S. Pat. No. 5,103,364 to Kamp; U.S. Pat. No. 5,099,382 to Eppinger; U.S. Pat. No. 4,568,804 to Luehring and U.S. Pat. No. 4,323,871 to Kamp et al.; the subject matter of each of which is herein incorporated by reference.
Accordingly, an object of the present invention is to provide a circuit interrupting device that is compact and less expensive than conventional circuit interrupting devices.
Another object of the present invention is to provide a circuit interrupting device that can be retro-fit to various existing circuit interrupter mountings of a power distribution system pole.
A further object of the present invention is to provide a circuit interrupting device that can be easily removed from the system, facilitating maintenance and visually indicating to a lineman that the current path of the system has been interrupted.
Yet another object of the present invention is to provide a circuit interrupting device that is maintained at the same potential as the distribution system.
Still another object of the present invention is to provide a circuit interrupting device that includes an handle and lever mechanism actuated by the electronic control of the device to allow a lineman to manually interrupt the circuit.
Another object of the present invention is to provide a circuit interrupting device that prevents closure of the current path during a fault without the need for separate and additional parts for a trip free mechanism.
The foregoing objects are attained by a circuit interrupting device for use with an electrical power distribution system, comprising a circuit interrupter that includes a primary contact and a movable contact movable relative to the primary contact between a closed position allowing current to pass through the circuit interrupter and an open position separating the contacts and preventing the current from passing through the circuit interrupter. An actuator is coupled to the circuit interrupter. The actuator includes a shaft coupled to the movable contact of the circuit interrupter for substantially simultaneous movement without insulation being disposed between the shaft and the movable contact. The shaft moves the movable contact from the closed position to the open position upon occurrence of a fault current. An electronic control is electrically connected to the actuator and communicating with the actuator to trigger the shaft to move the movable contact of the circuit interrupter from the closed position to the open position.
The foregoing objects are also attained by a circuit interrupting device for use with an electrical power distribution system, comprising a circuit interrupter that has a closed position allowing current to pass through the circuit interrupter and an open position preventing the current from passing through the circuit interrupter. An actuator is coupled to the circuit interrupter. The actuator moves the circuit interrupter between the closed and open positions upon occurrence of a fault current. First and second terminals are electrically connected to the circuit interrupter and are adapted for electrical connection to the power distribution system. A current path is defined between the first terminal, the circuit interrupter, and the second terminal, allowing current of the power distribution system to pass through the current path so that the potential of the circuit interrupter is the same as the potential of the power distribution system. The circuit interrupter and the actuator are not mounted in a grounded container, and the first terminal, the circuit interrupter, the actuator, and the second terminal are ungrounded.
The foregoing objects are also attained by a circuit interrupting assembly for an electrical power distribution system, comprising a first insulator adapted for connection to the power distribution system. The insulator has a first conductive bracket. A circuit interrupting device is coupled to the first conductive bracket of the insulator. The circuit interrupting device includes a circuit interrupter that includes a dielectric housing with a primary contact and a movable contact enclosed therein. The movable contact is movable relative to the primary contact between a closed position allowing current to pass through the circuit interrupter and an open position separating the contacts and preventing current from passing through the circuit interrupter. An actuator is coupled to and disposed adjacent to the circuit interrupter. The actuator is received in a housing and includes a shaft coupled to the movable contact of the circuit interrupter for substantially simultaneous movement without insulation being disposed between the shaft and the movable contact. The shaft moves the circuit interrupter between the closed and open positions upon occurrence of a fault current. First and second terminals are electrically connected to the circuit interrupter. At least one of the first and second terminals is connected to the first conductive bracket. A current path is defined between the first terminal, the circuit interrupter and the second terminal, allowing current of the power distribution system to pass through the current path so that the potential of the circuit interrupter is the same as the potential of the power distribution system. The circuit interrupter and the actuator are not mounted in a grounded container. The first terminal, the circuit interrupter, the actuator, and the second terminal are ungrounded.
The foregoing objects are also attained by a recloser for use with an electrical power distribution system, comprising a circuit interrupter including a primary contact and a movable contact movable relative to the primary contact between a closed position allowing current to pass through the circuit interrupter and an open position separating the contacts and preventing current from passing through the circuit interrupter. An actuator is coupled to the circuit interrupter and includes a movable shaft coupled to the movable contact of the circuit interrupter for substantially simultaneous movement therewith and without insulation being disposed between the movable contact and the movable shaft. An electronic control is electrically connected to the actuator. The electronic control communicates with the actuator upon occurrence of a fault current to trigger the shaft to move the movable contact of the circuit interrupter from the closed position to the open position and to trigger the shaft to reclose the movable contact from the open position to the closed position upon termination of the fault current.
The foregoing objects are also attained by a recloser for use with an electrical power distribution system, comprising a circuit interrupter movable between a closed position allowing current to pass through the circuit interrupter and an open position preventing current from passing through the circuit interrupter. An actuator is coupled to the circuit interrupter and moves the circuit interrupter between the closed and open positions. A rotatable handle mechanism coupled to the actuator and movable between first and second positions corresponding to the closed and open positions of the circuit interrupter and adapted to move the actuator from the closed position to the open position. An electronic control is electrically connected to each of the actuator and the handle mechanism. The electronic control triggers the actuator to move the circuit interrupter from the closed position to the open position and triggers the handle mechanism to rotate from the first position to the second position. During fault conditions the electronic control triggers the actuator to move the circuit interrupter from the closed position to the open position and triggers the handle mechanism to rotate from the first position to the second position with the handle mechanism being incapable of moving the actuator from the open position back to the closed position.
By designing the circuit interrupter in the manner described above, the circuit interrupting device can be made lightweight and compact for removable mounting in various circuit interrupter mountings of a power distribution system. The device also provides a visual indication to a lineman of whether the circuit of the system has been interrupted in the lock-out condition.
Other objects, advantages and salient features of the invention will become apparent from the following detailed description, which, taken in conjunction with annexed drawings, discloses a preferred embodiment of the present invention.